Pharmacokinetics and clinical efficacy of cyclosporine treatment of dogs with steroid-refractory inflammatory bowel disease

The usual treatment of dogs with inflammatory bowel disease (IBD) consists of administration of immunosuppressive doses of steroids. However, some dogs are refractory to steroid treatment and pose a significant challenge to the veterinarian. Because cyclosporine A (cyA) has been shown to be effective in steroid-resistant IBD in humans, the purpose of this study was to investigate the pharmacokinetics and clinical efficacy of PO cyA treatment in dogs with steroid-refractory IBD (n = 14). All dogs were treated with cyA 5 mg/kg PO q24h for a period of 10 weeks. A clinical activity score was assigned to assess severity of clinical signs before and after treatment. The total number of infiltrating lymphocytes and T cells in duodenal biopsies were assessed before and after treatment in 9 dogs. In addition, serum concentration of cyA was measured in 8 dogs over a 24-hour period. Pharmacokinetic profiles in dogs with IBD were similar to those of healthy dogs. Improvement of clinical signs was observed in 12 of 14 dogs with IBD. Median clinical activity score after treatment with cyA was significantly reduced from a median score of 9 to a median score of 5 (P = 0.001). T cell numbers in duodenal biopsies were significantly decreased after treatment from a median +/- 95% range in the villous region of 28 (19-30) cells/10,000 microm2 before versus 7 (0-10)/10,000 microm2 after treatment, P = 0.01; and from a median +/- 95% range number in the crypt region of 15 (6-23) cells/10,000 microm2 before versus 4 (0-9)/10,000 microm2 after treatment, P = 0.02, implying T cell lysis as a possible mechanism of action. In conclusion, based on this small study, cyA appears to be an effective alternative drug in dogs with IBD that are refractory to immunosuppressive doses of steroids.

Cyclosporin A pharmacokinetics and efficacy in the treatment of atopic dermatitis in dogs

A series of experiments was conducted to study cyclosporin A (CsA) pharmacokinetics in dogs and the factors influencing variability of blood concentrations. In a first study, influence of feeding on drug absorption and blood profile was evaluated. Administration of CsA as micro-emulsion (ME) formulation with food decreased the bioavailability by 22% and increased the individual variability of drug absorption. In a second study, pharmacokinetic profiles from laboratory fasted beagle dogs receiving orally CsA ME formulation were analyzed. CsA was measured in blood samples by high-performance liquid chromatography (HPLC, 34 profiles) and fluorescent polarization immunoassay (FPIA, 16 profiles). A two-compartment model with first-order absorption was used to calculate the pharmacokinetic parameters. Using FPIA, blood concentrations were 1.5 to 1.7 times higher than when using HPLC, but elimination half-life and MRT were similar. The coefficient of variation of key pharmacokinetic parameters ranged from 27 to 34% following HPLC assay. The same range of variation was obtained after FPIA assay. In a third study, in a clinical trial evaluating CsA for the treatment of canine atopic dermatitis, a single blood sample was collected in dogs which had received CsA for 28 days. No significant correlation was found between clinical improvement and CsA blood concentrations. Considering the large margin of safety of CsA in dogs, the limited inter-individual variability and the lack of correlation between blood concentrations and clinical response, routine monitoring of blood CsA does not appear necessary in dogs with atopic dermatitis.

Remission of the clinical signs of atopic dermatitis in dogs after cessation of treatment with cyclosporin A or methyiprednisolone

Seventy-eight dogs with atopic dermatitis were treated for four months with either cyclosporin A or methylprednisolone. During the two months after the treatment ceased, 87 per cent of the dogs treated with methylprednisolone relapsed after a mean period of 27.9 days, whereas only 62 per cent of the dogs treated with cyclosporin A relapsed after a mean period of 40.7 days (P < .0.001). The clinical condition of the dogs was evaluated either when they relapsed, or two months after the treatment ceased if they had not relapsed. Both the skin lesions and pruritus increased significantly more markedly in the dogs treated with methylprednisolone than in those treated with cyclosporin A. At the end of the study the skin lesions were markedly less severe than before the therapy; in the dogs in both groups that did not relapse, the lesion score was improved by 77 per cent two months after the treatment had stopped, and in the dogs that did relapse the lesion scores had improved by 45 per cent and 35 per cent in the dogs treated with cyclosporin A and methylprednisolone, respectively. Pruritus remained well controlled in the dogs that did not relapse, but increased to baseline levels or close to baseline in the dogs that relapsed.

Fentanyl-induced chest wall rigidity and laryngospasm in preterm and term infants

OBJECTIVE

To assess the occurrence of muscle rigidity after fentanyl administration in premature and term neonates.

DESIGN

Prospective case series, observational study.

SETTING

A university hospital neonatal intensive care unit.

PATIENTS

8/89 preterm and term infants (25-40 wks gestational age) who received fentanyl for perioperative analgesia and sedation or intensive care procedures.

INTERVENTIONS

Mechanical or bag mask ventilation and antagonization with naloxone.

MEASUREMENTS AND MAIN RESULTS

We observed chest wall rigidity in 8 patients after low dosage of fentanyl (3-5 microg/kg body weight). All patients presented with respiratory distress, hypercapnia, and hypoxemia leading to bradycardia. In two patients, laryngospasm was noted and associated with muscle rigidity, thus making intubation impossible. Naloxone (20-40 microg/kg body weight) reversed the laryngospasm and muscle rigidity immediately, allowing restitution within 1 min. In our patient population, we found fentanyl-induced chest wall rigidity in 4% of neonates after fentanyl administration.

CONCLUSION

Even low doses of fentanyl can lead to thoracic rigidity in neonates. Additionally, we observed laryngospasm in two patients and speculate that it might be a variant of muscle rigidity.

Efficacy of an adulticide used alone or in combination with an insect growth regulator for flea infestations of dogs housed in simulated home environments

OBJECTIVE

To determine the effect of an adulticide on flea populations of dogs and to evaluate efficacy of combined use of the adulticide and an insect growth regulator (IGR) in dogs with experimentally induced flea infestations.

ANIMALS

40 adult Beagles.

PROCEDURE

Each group of 5 dogs was housed in a separate room. Each dog was infested 3 times with 50 fleas, and fleas were counted beginning on day -21. Groups of dogs and treatments (initiated on day 0) were as follows: 1, adulticide once; 2, adulticide on days 0 and 7; 3, adulticide on days 0, 3, and 7; 4, sham treatment; 5, IGR monthly; 6, IGR monthly plus adulticide once weekly for 6 weeks; 7, IGR monthly plus adulticide twice weekly for 6 weeks; 8, sham treatment. Flea counts were compared between treated and control dogs.

RESULTS

By 24 hours after initial treatment, all adult fleas but 1 were dead in treated dogs. In groups 1 and 3, populations increased to 15 to 20 fleas/dog 2 months after treatment, compared with 48 fleas/dog in group 4. After treatment, mean flea counts were significantly lower for groups 1, 2, and 3, relative to group 4. Efficacy of treatment for group 5, relative to group 8, was > 94% after day 84. Efficacy of treatment for groups 6 and 7 was 99% after day 28.

CONCLUSIONS AND CLINICAL RELEVANCE

Treatment with adulticide alone or in combination with an IGR had better efficacy, compared with sham treatment or IGR alone. Administration of adulticide twice weekly was not more efficacious than treatment once weekly.

[Quality assurance in therapy of mucoviscidosis: value of the Bonn patient information system]

BACKGROUND

Differences in the survival rates of patients in two large CF-clinics (Toronto, Boston) were explained by differences in dietary regimens: Toronto favoured a fat-enriched diet and had the better outcome. This example may explain how important high quality medical data are for improving treatment and prognosis of CF.

AIM

A local patient-information-system is described to improve internal and external quality control.

RESULTS

The system was developed over years in a fruitful collaboration between a realistic statistician and active CF doctors. It is easy to use and facilitates documentation, follow-up, researches and preparation of data for scientific presentation and clinical routine. Graphical outline may be used to motivate individual patients. Internal controlling for plausibility improves quality of data also serving the national system for quality control.

CONCLUSIONS

We believe, our system is able to improve internal quality control and to serve the national system for quality control very efficiently without additional workload of the local CF-clinic.

Treatment of metritis with antibiotics or prostaglandin F2 alpha and influence of ovarian cyclicity in dairy cows

From 4 dairy herds with a high prevalence of metritis, 153 cows with clinical metritis diagnosed at 30 days after calving were allotted randomly to 3 groups: (1) intrauterine antibiotics (chloramphenicol, framycetin) given in 3 doses, 1 week between doses (n = 53); (2) prostaglandin F2 alpha given IM in 2 doses, 14 days between doses (n = 61); and (3) control cows given a placebo (n = 39). To further evaluate the efficiency of the treatments, uterine swabs were prepared from 59 of the cows; Corynebacterium pyogenes was isolated in 51% of the cows. All isolated bacteria were susceptible to chloramphenicol and 85% to neomycin and related antibiotics (framycetin). The overall clinical recovery rates, estimated by 60 days after parturition, were identical (49%) in the 2 treated groups vs 33% in controls. The mean interval from calving to conception was 147 days in the controls and was shortened by 16 days in group 1 and 24 days in group 2. The physiologic status, ie, ovarian cyclicity, was shown to exert a significant influence on the time required for recovery. On the average, anestrous cows recovered in 14 days and conceived 34 days later than did cycling cows.